build(deps): bump django from 1.11.20 to 1.11.29 in /iceweasel

Bumps [django](https://github.com/django/django) from 1.11.20 to 1.11.29.
- [Release notes](https://github.com/django/django/releases)
- [Commits](django/django@1.11.20...1.11.29)

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

iceweasel/requirements.txt

@@ -15,7 +15,7 @@ chardet==3.0.4
 Cheetah==2.4.4
 Click==7.0
 cryptography==2.0.3
-Django==1.11.20
+Django==1.11.29
 django-auth-ldap==1.7.0
 django-bootstrap3==11.0.0
 django-celery==3.3.0